The invention relates to deformation components and a documentation system for deformable components for use in a motor vehicle.
A number of components which are to comply with safety criteria, especially in crash situations, are used in motor vehicles. These components are designed to be able to absorb at least part of the energy of impact in a crash situation, such as a collision accident, and so can largely prevent injury to occupants. Such deformation components are employed, for example, in the area of the rear roof frame, in order to be able to meet with adequate reliability the head impact criteria as provided by FMVSS 201. According to FMVSS 201, the head injury force as measured by the HIC(d) (head injury criterion) in the case of impact on a head model at certain points in the interior of a motor vehicle must be less than 1000.
Such elements conventionally consist of various foamed plastics (such as EPP or PU), but ribbed packages of injection molded plastic, metal honeycombs, flex tubing, deformation plates, and the like are also used. Documentation in assembly (by the supplier or by the vehicle maker) is becoming increasingly difficult because of the increasing number of deformation components. For the sake of passenger safety and from the viewpoint of legal liability of the manufacturer of vehicles it is absolutely indispensable to produce complete documentation. After vehicles have been manufactured it is no longer possible to monitor the presence and correct installation of deformation components by optical means, since the elements are mostly concealed when installed. In installation it may happen, for example, that deformation components which were not at all provided for a specific position are nevertheless installed in this position. Hence deformation components which are too small are installed, or ones which are too large are forced into the wrong position. It must be possible to detect such errors after installation as well.
Hence the object of the invention is to develop a deformation element which is simple to manufacture and which makes it possible to identify this element after installation as well and to ensure correlation of data with the deformation element.
The invention is based on the determination that this object can be attained by means of a deformation element permitting contact-free identification, one which may be manufactured by conventional means, and one whose identification characteristics do not change.
It is claimed for the invention that this object is attained by means of a deformation component for use in a vehicle, one having at least one passive identification element as an integrated component which performs a read-only function. Vehicle parts are designated as deformation components which represent energy absorbing impact elements, in doors for example, as well as reinforced body structures on side sills and roof pillars. These parts are also designated as paddings. The deformation component claimed for the invention has an identification element as an integral component. Hence this element is joined to the deformation component so that it cannot be lost. Consequently, it is not possible for the identification element to be removed without destroying the deformation component. This ensures that manipulation such as replacement of identification elements can be prevented.
In addition, the identification element claimed for the invention is designed so that it performs a read-only function exclusively, that is, any data stored in the identification element can only be retrieved, or so that the identification element provides, on the basis of its structure, information regarding the deformation component into which it is integrated. On the other hand, in the case of the identification element claimed for the invention it is not possible to alter it and any data stored in it or to store other data in it after manufacture of the deformation component has been completed. During manufacture of the deformation component data are associated with the identification element which either are stored in this element or are documented by being entered in a list in which a relationship is established between the identification element and the features of the deformation component. This identification element is then entered in the corresponding deformation component. Consequently, after the deformation component has been completed it is not possible for the vehicle manufacturer or, for example, the customer service, to alter the data, even inadvertently. Since the identification element represents an integral component of the deformation component, the identification element is entered into or applied to the deformation component during manufacture of the latter. Unlike identification elements which are applied during assembly of a motor vehicle to deformation components which have already been produced, inadvertent erroneous association of an identification element with a deformation component is prevented in the case of the deformation component claimed for the invention. Such securing of data and their coordination with deformation components is indispensable for safety engineering reasons. At the same time, because of the passive design of the identification element it is not necessary to provide power supply for the identification element in the deformation component. The identification element is designed as an information carrier which is passive in operation, that is, an element from which data or information are scanned but one which need not deliver such data without external intervention. Consequently, provision of a power supply in the deformation component is not necessary in the case of the passive identification element used as claimed for the invention. Hence the identification element may be very small in size and accordingly does not decisively affect the properties, in particular the ability of the deformation component to absorb energy.
In one embodiment the identification element may be nondetachably embedded in foam in the deformation component. In the case of deformable components which for energy absorption purposes consist of plastic, especially foam plastic, the identification element may be introduced into the deformation component during manufacture, optionally after storage of data. In this way it can be additionally protected from external influences and temperature changes during installation in the motor vehicle during assembly and in the finished vehicle.
The identification element may, however, also be nondetachably mounted on the deformation component. In this embodiment the identification element may, for example, be mounted on the deformation component with adhesive. This embodiment is available, for example, for deformation components, especially metal deformation components, which are to be used in parts of a vehicle which are covered by sheathing and to which access or with which unintentional contact is prevented. For example, an identification element may be secured to a deformation component by an adhesive which is to be used in the roof structure of the vehicle. This deformation component is separated from the passenger compartment at least by the vehicle roof and the identification element is accordingly protected.
In a preferred embodiment the identification element is represented by a transponder. A transponder generally consists of a data storage medium and a coil or antenna for reception of energy and transmission of stored data. Characteristics of the deformation component are stored in the storage medium during manufacture of the deformable component and may be retrieved from the medium. Operating in conjunction with the data storage medium is an antenna or coil which serves to receive a signal, generally a field of a reading device, and over which data from the identification element may be transmitted to a scanning unit. About five billion combinations may be programmed by use of commercially available transponders and so the correct deformation component can be correlated with each building point, that is, with each position in the vehicle. In addition, transponders are designed to be insensitive to smoke, steam, liquids, various acids, dirt, and within certain limits also to physical damage and thermal influences. Moreover, disassembly of the passive transponder is not necessary, since its service life is virtually unlimited, the device taking its energy from a frequency field generated by a scanning device and so not requiring a battery or other power supply.
In another preferred embodiment the identification element is represented by a coil. In an embodiment such as this no special data may be stored in the identification element. Rather coordination of the deformation component during readout is made possible by the inductivity of the coil used in proportion to the length of the wire. This embodiment represents a considerable structural simplification, since only one coil needs to be mounted in the deformation component. Coordination of corresponding coils with specific deformation components, and thus properties with the deformation components, can be accomplished manually in this embodiment but may also be carried out automatically, in that the scanning unit, which recognizes a coil as a specific coil on the basis of its inductivity, takes from a data bank data which are assigned to this coil.
The invention also relates to a documentation system which comprises at least one deformable component with a passive, inductive identification element which performs a read-only function as an integral component and which has a central unit from which information stored in individual identification elements may be scanned and processed. A documentation system such as this also makes it possible to check a finished vehicle to determine if all the deformation components are present as prescribed and have been installed in the proper locations. The central unit may comprise a read feature and optionally a processing unit as well. Depending on the embodiment of the central unit, the data stored in the deformation component are, for example, scanned and stored, scanned and compared with previous data, or scanned and presented in optical form. The central unit may in this instance be a stationary or a mobile unit. In the first instance it may be a question, for example, of a unit installed in the vehicle itself which emits a signal whereby antennas or coils activate deformation components installed in the vehicle, or again whereby data received by the identification elements are processed and, for example, compared with an assigned value. If the central unit is a mobile unit, it may be moved to the vehicle as required, for example, in final inspection of assembly of a vehicle or after completion of repair work, and in particular may be built into the vehicle.
It is claimed for the invention that the central unit may be connected to a vehicle immobilizer system. In this embodiment it may be made certain that all prescribed deformable components have been installed, for example, after servicing of a vehicle by customer service. For this purpose the central unit may compare the assigned data with the data received by the individual deformation components and prevent departure of the vehicle in the event of absence or defective installation of a deformable component. The central unit may be connected or coupled to conventional electronic vehicle immobilizer systems.